Quarter	Millions of US Dollars
1997-07-01	0
1997-10-01	0
1998-01-01	0
1998-04-01	100
1998-07-01	100
1998-10-01	100
1999-01-01	100
1999-04-01	0
1999-07-01	150
1999-10-01	150
2000-01-01	300
2000-04-01	361
2000-07-01	206
2000-10-01	209
2001-01-01	56
2001-10-01	0
2002-01-01	150
2002-04-01	0
2002-07-01	0
2002-10-01	0
2003-01-01	0
2003-04-01	0
2003-07-01	0
2003-10-01	30
2004-01-01	30
2004-04-01	280
2004-07-01	310
2004-10-01	380
2005-01-01	530
2005-04-01	513
2005-07-01	508
2005-10-01	558
2006-01-01	783
2006-04-01	1110
2006-07-01	1102
2006-10-01	1652
2007-01-01	1277
2007-04-01	1067
2007-07-01	1050
2007-10-01	350
2008-01-01	1177
2008-04-01	1202
2008-07-01	1502
2008-10-01	2451
2009-01-01	1925
2009-04-01	1550
2009-07-01	1450
2009-10-01	866
2010-01-01	836
2010-04-01	1294
2010-07-01	1766
2010-10-01	1896
2011-01-01	1946
2011-04-01	3613
2011-07-01	2947
2011-10-01	2562
2012-01-01	4260
2012-04-01	3085
2012-07-01	4954
2012-10-01	4796
2013-01-01	4150
2013-04-01	3606
2013-07-01	1756
2013-10-01	1781
2014-01-01	831
2014-04-01	375
2014-07-01	375
2014-10-01	1386
2015-01-01	2145
2015-04-01	3109
2015-07-01	3450
2015-10-01	2444
2016-01-01	3147
2016-04-01	4897
2016-07-01	4991
2016-10-01	5663
2017-01-01	6485
2017-04-01	7223
2017-07-01	8591
2017-10-01	8650
2018-01-01	6123
2018-04-01	6533